Participants
Selected studies included 1473 patients, who presented 1656 episodes of acute asthma. A higher percentage of males than females were enrolled in all the studies (Table 1). The age range of the enrolled patients was between 0.58 yrs. to 13 yrs. Two studies21,26 reported younger patients (mean age 12.4 months21 and 19 months26); however, none of them enrolled patients with bronchiolitis or first wheezing episode.
Four studies20,25,26,27 reported the family history of asthma (12% to 75% of the patients included had a positive family history). Only two studies26,28 reported the positive asthma predictive index (API) status (30–38% had positive API). Six studies20,22,23,25,26,28 reported the use of ICS in the past (range from 20% to 100%). Sung et al.20 and Upham et al.23 stratified patients according to the use of ICS, while Nuhoglu et al.22 and Alangari et al.25 only reported the prevalence of ICS used. In the Razi et al.26 trial, the use of ICS was a mandatory inclusion criterion, but in the Razi et al.28 trial, patients with budesonide more than 400 mcg/day or those who change their doses in the last 2 months were excluded. The acute asthma severity scores at randomization were moderate to severe in four studies23-26, but using different clinical scores (Table 1).